In-fibre second-harmonic generation with embedded two-dimensional materials

Silica-based optical fibres are a workhorse of nonlinear optics, providing ready access to a range of nonlinear phenomena including solitons and self-phase modulation. However, they have one fundamental limitation: due to the amorphous nature of silica, they do not exhibit second-order nonlinearity, except for negligible contributions from surfaces. Here we demonstrate second-harmonic generation in functionalized optical fibres by using a monolayer of highly nonlinear MoS2 directly grown on the fibre's core. The MoS2-functionalized fibre exhibits a second-order susceptibility (chi((2))) value of 44 pm V-1 and a second-harmonic generation conversion efficiency of 0.2 x 10(-3) m(-2) W-1. This approach is scalable and can be generalized to other transition metal dichalcogenides and a wide range of waveguide systems. Our results demonstrate a new approach towards efficient in-fibre second-harmonic generation sources and may establish a platform for chi((2))-based nonlinear fibre optics, optoelectronics, photonics platforms, integrated optical architectures and active fibre networks. In-fibre second-harmonic generation is demonstrated in all-silica optical fibres by growing MoS2 monolayers directly onto the fibre's core.

Automated summary

This study demonstrates a method to achieve second-harmonic generation in functionalized optical fibers by directly growing highly nonlinear MoS2 monolayers on the fiber's core. The approach is scalable and can be generalized to other materials and waveguide systems.